The invention involves a method and apparatus for avoiding damage to supporting elements which may be arranged at regular or irregular intervals along a continuously moving cast metal strand, resulting from a cutting torch flame which is arranged above the cast metal strand and at right angles thereto. During a cutting operation, the cutting torch moves at the same speed and in the same direction as the cast metal strand until the cut has been completed.
In accordance with the invention, each supporting element pivots out of the support position, individually and sequentially, as the torch flame approaches, with the pivoting movement being generally parallel to the strand path of movement. Such pivoting action serves to avoid any undesirable heating of the supporting elements, which typically are rolls. Because the support rolls tend to receive heat from only one direction, it is difficult to dissipate such heat without subjecting the roll surface to stress from expansion. Heat dissipation and functional operation of the supporting element bearings can be further affected in an undesirable manner by the build-up of slag thrown by the cutting torch unless the roll is properly protected from such build-up. The slag is caused by the cutting flame which burns the strand material forming a spray cone of the slag.
It has been proposed in the past (German DT-OS 1914223) to diminish the undesirable effects of the cutting torch flame on the supporting elements by either arranging the supporting elements in the manner of a chain and moving the supports along at the same speed as the cast metal strand and cutting torch carriage, or else moving the supporting elements out of the way until the cutting flame has passed. However, the synchronism of supporting element and cutting flame does not necessarily avoid the heating of the supporting elements adjacent the torch. Moreover, the pivoting of supporting elements may result in a lack of support of the still-warm cast metal strand if too many are pivoted at the same time. When tilting several rolls simultaneously, considerable flexural elongation of the strand can result and the cast metal strand might buckle severely.
The present invention is based on the necessity of supporting medium and heavy cast metal strands as uniformly and continuously as possible. Removal of the supporting elements must be limited as much as possible in both time and number. Simultaneous tilting of all or several of the supporting elements, according to past practices, can be done only when dealing with minor supporting requirements such as for billets or narrow and/or thin slabs involving relatively light weights per meter of strand length. On the other hand, such practices are disadvantageous even for billets, because a low number of supports causes the spacings between supporting elements to become undesirably large.
Thus, the invention provides a method and means to achieve the greatest protection of the supporting elements against the cutting torch flame while at the same time most effectively providing support for the cast metal strand. The arrangement of the invention is suitable for use in connection with supporting elements arranged in regular and irregular intervals, as well as for bilaterial supporting elements for tilting into parallel position when employing medium and, particularly, heavy cast metal strands.